CTX001 is an investigational ex vivo CRISPR gene-edited therapy for patients suffering from β-thalassemia and sickle cell disease in which a patient’s hematopoietic stem cells are engineered to produce high levels of fetal hemoglobin (HbF; hemoglobin F) in red blood cells. A Phase 1/2 Study of CTX001 is currently enrolling patients. CTX001 is being developed under a co-development and co-commercialization agreement between CRISPR Therapeutics and Vertex Pharmaceuticals.